The proposed research will obtain longitudinal data from a high- risk population of unmarried adolescent women presenting for prenatal and obstetrical services at a large urban teaching hospital. The study's primary goal is determination of the interrelationships between pre-pregnancy drug use and abuse, early pregnancy, and child-bearing, and post-pregnancy patterns of drug use unprotected sexual activity, repeat pregnancy, and mother and infant development. If warranted, results from this study will provide the basis for a multiple state, multi-site investigation of substance use among unmarried pregnant and parenting adolescent women. The ultimate goal for this line of research is provision of empirical foundations for designing and testing innovative interventions that may be used to prevent or ameliorate adverse consequences of drug use for sexually active school drop-outs and other high-risk adolescent female populations. Initial data collection will be done in conjunction with prenatal care visits to two large hospitals serving low income populations. Young mothers' need for pediatric and post-natal care services following delivery will provide an excellent mechanism for systematic follow-up. Data collection at 1, 6, 12, and 18 months after pregnancy resolution will constitute the prospective, longitudinal portion of the study.